1. Technical Field
The present invention relates to a fluid supply device that supplies fluid from a main tank through a sub tank to a head, to a printing device, and to a method of controlling fluid supply devices.
2. Description of Related Art
One example of a fluid supply device is a device that is incorporated in a printer connected to a personal computer, for example, and supplies fluid ink to the print head.
Japanese Unexamined Patent Appl. Pub. JP-A-2001-71530, for example, teaches a fluid supply device that has a printing control means for controlling a printing means, a maintenance operation control means, and an ink consumption control means, calculates ink consumption from the cleaning operations and ink droplet discharge count, and warns the user when the ink must be replaced.
The technology taught in JP-A-2001-71530 determines the ink consumption from the ink droplet discharge count and estimates the remaining ink volume, but the detection accuracy of this technology is not high. As a result, the threshold value for determining the ink end is set higher than the actual ink end level to provide a safety margin, the ink cartridge must therefore be replaced while some amount of ink is left, and ink is thus wasted.